Can’t hide Site Title

Hi!

Quick Note: I know I already posted a thread about my widgets problem, but a lot of people are always saying ‘Make a new post for that!’, so here I am.

My problem is that I want to hide my site title and description, but I can’t. I editet the stylesheet, I used custom css and tried to fix it with the plugin ‘simple css’, but it didn’t work. Does the site title have a different name in the style sheet? That’s what I wrote everywhere (custom css, stylesheet, simple css):

#site-title {
  display:none;

I don’t understand what I’m doing wrong. The only explanation I can think of is that the site title and description are called something else in the code. I don’t know much about coding, so that’s all I can think of.

Thanks in advance!
-Liiki